1. Field of the Invention
The present invention relates to a protection key for hardware and an information management system, especially a technology for enhancing confidentiality of data within the protection key.
2. Description of the Related Art
As related art, a protection key for hardware, called “dongle”, is used to prevent illegal duplication of software. The dongle is connected to an I/O port of a computer via a connector. The computer identifies an allowed dongle, and then the computer runs the software. The dongle includes “dongle data”, for example, a serial number, a product identification of the software, or a company identification provided by the company, so that the computer can determine whether to grant permission for the use of the software. When the computer grants the permission, the software matching the dongle data can be used. The computer provided with the dongle retrieves key information from the dongle, generates a cryptography key based on the key information by an encryption algorithm, and encrypts the general data based on the cryptography key so as to transmit the general data to the computer peripherals.
As shown in Japanese laid open (Kokai) No. 2000-151580, a Digital Block Cipher based on a Chaos Block Cipher Algorithm is known as a cryptography technology. Also, a well-known cryptography technology is shown in Japanese laid open (Kokai) No. 2001-175468 and No. 2002-116837.
However, the dongle data carried between the computer and the dongle is not encrypted in the related art. Therefore, the dongle data might be exposed to a risk of data leakage. Consequently, illegal copying and illegal use of the software cannot be prevented.